As formats of a video footage handled in broadcast, there are an interlaced video signal of standard definition (SD), interlaced video signal (1080i) of high definition (HD), and progressive video signal (720p). When a video footage based on different formats is reproduced as a video signal of a specified format, a multiformat video playback device is used.
This multiformat video playback device decodes an input video footage, converts the decoded video footage into a progressive signal when the video footage is an interlaced signal, up-converts or down-converts the resultant into a video signal of a specified format and, when the specified format is an interlaced format, reads the video signal in the interlaced format, thereby reproducing a video signal in the specified format.
It should be noted that, in the multiformat video playback device, an up/down converter provided with both the up-conversion function and down-conversion function is used. The up/down converter can immediately cope with both up-conversion and down-conversion by switching corresponding to the input/output format. However, the up/down converter immediately copes with the switching instruction, and hence, irregularities occur in the video when conversion is switched from up-conversion to down-conversion or from down-conversion to up-conversion in some cases.